Water coolers are known utilizing thermoelectric modules to freeze water in contact therewith to form ice in containers and using the ice to cool the remaining water in the containers. Usually the containers have a water supply connected thereto either from replenishable bottles or a water supply.
Examples of water coolers having thermoelectric modules to cool drinking water are disclosed by M. Alex in U.S. Pat. No. 3,088,289 and T. M. Elfving in U.S. Pat. No. 4,055,053. Elfving's cooler produces ice which is intermittently released from the thermoelectric module into a water reservoir. The energy stored in the ice cools the water while more ice is formed by the thermoelectric module.
C. P. West and D. B. Neuwen describe in International Publication No. WO 93/08432, a water cooling system having a thermoelectric module to form ice used to cool water in a reservoir. A photo-optic sensing device is used to determine when ice produced on the thermoelectric module has a predetermined mass large enough to be released into the reservoir. The sensing device generates a light beam over the thermoelectric module. As the ice grows on the thermoelectric module, the light beam is broken, which causes the electric power supply to be turned OFF. Heat is allowed to flow from a heat sink through the thermoelectric module to defrost a part of the ice immediately adjacent the thermoelectric module. This allows the ice to float towards the surface of the water in the reservoir. As soon as the ice moves out of the light beam, the electric power is again supplied to the thermoelectric module to begin generation of the next mass of ice.